Alice Keeler is just genius at explaining new features of Google Drive! The key takeways from this post for me are:
1) Make sure you change your settings on the folder you are sharing. If you're going to use an email list, you can still limit sharing to specific people, but you need to add their email addresses. That can be a pain for teachers who have spent time typing in all the addresses. This is why I love the second key takeaway...
2) If you're sharing a folder with students, make a quick Google form to collect their addresses, then copy and paste into your "share with specific people" email list! If you do this for a class, everything you share in that folder will be accessible to students. Keep adding documents, and all students will have access to them! Brilliant! This would also be great for sharing information with parents, too. It certainly would save you a lot of typing!